HDDS-12062. Recon - Error handling in NSSummaryTask to avoid data inconsistencies.

hadoop-ozone/recon/src/main/java/org/apache/hadoop/ozone/recon/spi/impl/OzoneManagerServiceProviderImpl.java

@@ -501,7 +501,9 @@ ImmutablePair<Boolean, Long> innerGetAndApplyDeltaUpdatesFromOM(long fromSequenc
       }
       for (byte[] data : dbUpdates.getData()) {
         try (ManagedWriteBatch writeBatch = new ManagedWriteBatch(data)) {
+          // Events gets populated in events list in OMDBUpdatesHandler with call back for put/delete/update
           writeBatch.iterate(omdbUpdatesHandler);
+          // Commit the OM DB transactions in recon rocks DB and sync here.
           try (RDBBatchOperation rdbBatchOperation =
                    new RDBBatchOperation(writeBatch)) {
             try (ManagedWriteOptions wOpts = new ManagedWriteOptions()) {

hadoop-ozone/recon/src/main/java/org/apache/hadoop/ozone/recon/tasks/ContainerKeyMapperTask.java

@@ -34,8 +34,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import org.apache.commons.lang3.tuple.ImmutablePair;
-import org.apache.commons.lang3.tuple.Pair;
 import org.apache.hadoop.hdds.conf.OzoneConfiguration;
 import org.apache.hadoop.hdds.utils.db.RDBBatchOperation;
 import org.apache.hadoop.hdds.utils.db.Table;
@@ -82,7 +80,7 @@ public ContainerKeyMapperTask(ReconContainerMetadataManager
    * (container, key) -> count to Recon Container DB.
    */
   @Override
-  public Pair<String, Boolean> reprocess(OMMetadataManager omMetadataManager) {
+  public TaskResult reprocess(OMMetadataManager omMetadataManager) {
     long omKeyCount = 0;
 
     // In-memory maps for fast look up and batch write
@@ -118,7 +116,7 @@ public Pair<String, Boolean> reprocess(OMMetadataManager omMetadataManager) {
                 containerKeyCountMap);
             if (!checkAndCallFlushToDB(containerKeyMap)) {
               LOG.error("Unable to flush containerKey information to the DB");
-              return new ImmutablePair<>(getTaskName(), false);
+              return buildTaskResult(false);
             }
             omKeyCount++;
           }
@@ -131,7 +129,7 @@ public Pair<String, Boolean> reprocess(OMMetadataManager omMetadataManager) {
           containerKeyCountMap)) {
         LOG.error("Unable to flush Container Key Count and " +
             "remaining Container Key information to the DB");
-        return new ImmutablePair<>(getTaskName(), false);
+        return buildTaskResult(false);
       }
 
       LOG.debug("Completed 'reprocess' of ContainerKeyMapperTask.");
@@ -142,9 +140,9 @@ public Pair<String, Boolean> reprocess(OMMetadataManager omMetadataManager) {
     } catch (IOException ioEx) {
       LOG.error("Unable to populate Container Key data in Recon DB. ",
           ioEx);
-      return new ImmutablePair<>(getTaskName(), false);
+      return buildTaskResult(false);
     }
-    return new ImmutablePair<>(getTaskName(), true);
+    return buildTaskResult(true);
   }
 
   private boolean flushAndCommitContainerKeyInfoToDB(
@@ -189,7 +187,8 @@ public Collection<String> getTaskTables() {
   }
 
   @Override
-  public Pair<String, Boolean> process(OMUpdateEventBatch events) {
+  public TaskResult process(OMUpdateEventBatch events,
+                            Map<String, Integer> subTaskSeekPosMap) {
     Iterator<OMDBUpdateEvent> eventIterator = events.getIterator();
     int eventCount = 0;
     final Collection<String> taskTables = getTaskTables();
@@ -246,18 +245,18 @@ public Pair<String, Boolean> process(OMUpdateEventBatch events) {
       } catch (IOException e) {
         LOG.error("Unexpected exception while updating key data : {} ",
             updatedKey, e);
-        return new ImmutablePair<>(getTaskName(), false);
+        return buildTaskResult(false);
       }
     }
     try {
       writeToTheDB(containerKeyMap, containerKeyCountMap, deletedKeyCountList);
     } catch (IOException e) {
       LOG.error("Unable to write Container Key Prefix data in Recon DB.", e);
-      return new ImmutablePair<>(getTaskName(), false);
+      return buildTaskResult(false);
     }
     LOG.debug("{} successfully processed {} OM DB update event(s) in {} milliseconds.",
         getTaskName(), eventCount, (System.currentTimeMillis() - startTime));
-    return new ImmutablePair<>(getTaskName(), true);
+    return buildTaskResult(true);
   }
 
   private void writeToTheDB(Map<ContainerKeyPrefix, Integer> containerKeyMap,